Kenworth T680 Next Gen Sets New Fuel Economy Benchmark in Real-World Testing

Kenworth T680 Next Gen Fuel Economy Results

PACCAR's Kenworth division has released results from an extensive 50,000-mile real-world fuel economy evaluation of the T680 Next Gen, showing an average of 9.2 MPG across varied terrain and weather conditions. The test, conducted in partnership with three major fleets, ran from October through February covering routes across the continental United States.

Testing Methodology

The evaluation included 15 trucks operating in three distinct corridors: the I-10 southern route from Jacksonville to Los Angeles, the I-80 corridor from New York to San Francisco, and the I-35 route from Laredo to Duluth. Each truck was loaded to a gross vehicle weight of 78,000 lbs and operated by experienced drivers following normal fleet protocols. Trucks were equipped with the PACCAR MX-13 engine rated at 510 HP and 1,850 lb-ft of torque.

Key Findings

The best-performing truck achieved an impressive 9.8 MPG on the I-10 southern corridor, while the fleet average across all routes came in at 9.2 MPG. Contributing factors included the improved aerodynamic package with an optimized bumper design, new chassis fairings, and a redesigned roof fairing that reduces drag by 7% compared to the previous model. The PACCAR TX-12 automated transmission also played a significant role, with its predictive cruise control using GPS terrain data to optimize shift points.

Fleet Implications

At current diesel prices averaging $3.85 per gallon, the fuel savings translate to approximately $8,500 per truck annually for a fleet running 120,000 miles per year. Several participating fleets have already placed orders for additional units, with Werner Enterprises committing to 500 T680 Next Gen tractors for delivery throughout 2026.